Controllable preparation of VO2@m-SiO2 and its light transmittance and thermal insulation properties of PVB composite films

In this study, a hybrid approach using the Stöber and solvent extraction techniques was employed to synthesize mesoporous silicon-coated VO2 nanomaterials (VO2@m-SiO2, VmS) with controllable pore sizes and shell thicknesses. This synthesis was aimed at elucidating the influence of mesoporous silicon coatings on the thermochromic effect and optical properties of VO2. Experimental findings reveal that the mesoporous silica architecture markedly improve the phase-transition hysteresis of VO2 while mitigating the Mie effects attributable to particle coarsening, under the appropriate shell thickness. Furthermore, concomitant with the enlargement of the mesoporous aperture, the Tlum and ΔTsol of the VmS/PVB films also exhibit upward trends. Tlum reaches 73.33% and 62.24% in VmS3/PVB and VmS5/PVB, peak ΔTsol reaches 5.16% in VmS5/PVB. The facile synthesis procedure of VmS, in conjunction with its superior performance across phase transition, optics, and thermal insulation metrics, offers a viable pathway for industrial-scale deployment of VO2(M) in smart window applications.